I get an error when I follow your steps for compilation

[Lqs66]

          To instrument ArduPilot using LLVM, Clang should be substituted for GCC as the compiler prior to compilation. For guidance on altering the compiler and platform target, please consult the files ARI/ardupilot/source_me_sitl_bc_step_zero.txt and ARI/ardupilot/wscript.

Originally posted by @J1nwenWang in #1 (comment)

I use the following command:
CC=clang CXX=clang++ CXXFLAGS="-O0 -g --target=arm-linux-gnueabihf -I/usr/arm-linux-gnueabihf -I/usr/arm-linux-gnueabihf/include/c++/9" ./waf configure --board=navio2 && ./waf copter
The error is as follows:
"fatal error: 'bits/libc-header-start.h' file not found
#include <bits/libc-header-start.h>"